import java.util.TreeSet;
import java.util.Iterator;

public class NonCompareTo{
    public static void main(String[] args){
        TreeSet<Test> t = new TreeSet<Test>();
        Test t1 = new Test();
        Test t2 = new Test();
        
        System.out.println("******************");
        
        t.add(t1);
        t.add(t2);
        
        for(Test item : t){
            System.out.println(item);
        }
    }
}

class Test{
    String name = "hahah";
    String id = "ahhahj";
    Test(){
        
    }
    
    public String otString(){
        return "{hahahah}";
    }
}
